Atlas Copco ER S-1, Инструкция, Страница: 24 / 40

20/06/2011 PM 9845 0512 02 Page 22 of 36
In case thermostatic valve in compressor is 75°C (tropical thermostat), please contact your official Service Contact.
The thermostatic valve installed in the ER kit must always have a lower temperature range than the thermostatic valve
installed in the compressor.
For ER installation on GA tropical variants, please contact Atlas Copco.
7.2. Energy recovery system is turned on
In this case, the lever (Figure 14-26) of the 1st bypass valve (Figure 14-7) of the ER unit should be turned in fully clockwise.
Always turn the lever (Figure 14-26) all the way in or out. Do not position it anywhere in between both ends.
Compressor start-up
When the compressor is started in cold conditions, the oil temperature will be low. The 1st bypass valve (Figure 2-7) of the
ER unit shuts off the oil supply from the heat exchanger (Figure 2-8) and the 2nd bypass valve (Figure 2-14) shuts off the oil
supply from the main oil cooler (Figure 2-23) to prevent the compressor oil from being cooled. The oil flows from the
separator (Figure 2-12) through the oil filter (Figure 2-24) to the compressor element (Figure 2-25).
The entire energy input is used to rapidly warm up the compressor oil. No energy is recovered.
Maximum energy recovery
When the oil temperature reaches approx. 40°C, the 1st bypass valve (Figure 2-7) of the ER unit starts opening the oil
supply line from the heat exchanger (Figure 2-8). When the oil temperature rises to approx. 55°C, all the oil passes through
the heat exchanger. The oil from the heat exchanger outlet flows via the oil filter (Figure 2-24), the compressor element
(Figure 2-25) and the separator (Figure 2-12) back to the inlet of the heat exchanger. The 2nd bypass valve (Figure 2-14)
continues to bypass the main oil cooler (Figure 2-23) as long as the oil temperature after the heat exchanger (Figure 2-8)
remains below 75°C.
The heat exchange between the compressor oil and the heat recovery water is at its maximum.
NOTES:
•
The opening temperature depends on which insert is placed in the 1st bypass valve of ER unit.
•
The amount of recovered energy depends on the load cycle of the compressor (particularly in VSD applications).
Low consumption of recovered energy
In this case, the temperature of the oil leaving the heat exchanger (Figure 2-8) may be too high for the oil to be injected into
the compressor element (Figure 2-25). Therefore, the 2nd bypass valve (Figure 2-14) will open the oil supply line from the
main oil cooler (Figure 2-23) to allow the hot oil to be cooled in this cooler.
The amount of energy supplied to the water is adjusted to the energy demand.
Recovery water flow too high or water inlet temperature too low
In this case, the temperature of the oil leaving the heat exchanger (Figure 2-8) may be too high for the oil to be injected into
the compressor element (Figure 2-25). Therefore, the 1st bypass valve (Figure 2-7) of the ER unit will partly shut off the oil
supply from the heat exchanger (Figure 2-8) to allow the cold oil from the heat exchanger to be mixed with the hot oil from
the separator (Figure 2-12).
Energy is transferred from the compressor oil to the water, but at a relatively low temperature level.